In order to prevent excessive fluid loss or bleeding during a surgical procedure, a surgeon can ligate or close various fluid ducts and/or blood vessels before severing those vessels. There are many types of mechanisms or devices for shutting off the vessels such as ligating clips, hemostatic clips, and the like. In some instances the surgeon will tie a ligature or suture about a vessel to close or shut the vessel. Ligating clips are well known in the art. Many of the clips are metal and comprise a pair of legs which are connected at one end. The vessel to be ligated is placed between the legs and the legs are forced together about the vessel to close the vessel. Clips have also been developed from plastic materials. However, since plastics do not have the same strength and malleability characteristics as metals, the plastic clips typically include some type of locking mechanism so that when the legs are urged together about the vessel they are locked in a closed position.
Ligating clips should ensure closure of the vessel. That is, they should completely shut off blood flow or other fluid flow and not allow leakage. Also, the clips should remain closed, should not open or break, and should not slip or slide out of position or off the vessel. While it does not take much force to collapse and close a vessel, some clips can require substantial force to close or change configuration so that once closed, the clip will remain in its closed position.
In minimally invasive surgery, in particular, endoscopic surgery, it has become desirable to provide smaller instruments capable of reaching surgical sites through smaller access ports. Smaller incisions cause less damage in accessing the surgical site and the access wounds from such incisions heal faster. The size of the instrument is dictated, in general, by the size of the clip as it is passed through the clip applying instrument to its business end and the size of the jaws used to crush the clips closed. Clips are typically passed through the clip applying instrument in an open position so as to allow the clip to capture a tissue structure to be ligated before the jaws crush the clip closed over the structure.
In endoscopic surgery, the business end of the instrument is placed within the body through an appropriate cannula, body canal, or small incision. The manipulation of that business end by the surgeon is accomplished outside the body. As a result, it becomes more difficult to control the business end of the instrument since it is further removed from the actual operation of the instrument. Any slight movement in the manipulation of the instrument outside the body is magnified at the business end of the instrument. Therefore, there is a greater chance in an endoscopic procedure that a slight movement of a clip applier as a clip is being closed will cause clip misplacement. This is particularly true considering that clips can require high force to effectively form over a tissue structure.